Issue 38

U. Haider et alii, Frattura ed Integrità Strutturale, 38 (2016) 305-318; DOI: 10.3221/IGF-ESIS.38.41 305 Mechanical behaviour and durability of high volume fly ash cementitious composites Usman Haider, Zdeněk Bittnar, Lubomír Kopecky, Petr Bittnar, Jiří Němeček Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic usmanhaider6886@gmail.com Asif Ali Department of Chemical Engineering, University of Engineering and Technology, Lahore, Pakistan Jaroslav Pokorny Department of Material Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic A BSTRACT . The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles. K EYWORDS . Cementitious matrix; Raw fly ash; Second layer particles; Third layer particles. Citation: Haider, U., Bittnar, Z., Kopecky, L., Bittnar, P., Němeček, J., Ali, A., Pokorny, J., Mechanical behaviour and durability of high volume fly ash cementitious composites, Frattura ed Integrità Strutturale, 38 (2016) 289-302. Received: 23.04.2016 Accepted: 15.07.2016 Published: 01.10.2016 Copyright: © 2016 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION ly ash produced from combusting coal is generated in excess of 750 million tons globally and at current coal combustion rate the world coal reserves will still last for about 150 more years [1-2]. Landfilling of fly ash was considered a viable solution, but new legislations in the world are increasing the costs of landfills. Thereby energy companies are themselves encouraging the research on fly ash not, only to reutilize the everyday produced fly ash, but as F